Questions about handling user files in Ethereum DApps.

I'm making Ethereum DApp now. DApp is made up of users who have relevant data, such as email, name, or profile picture. I want to store user information within IPFS like JSON object and use IPFS hash to refer to these information in the chain. How do I associate this data with a specific user? The subsequent interaction with DApp connects the user to the data stored in IPFS, which returns with a user account hash with a kind of password?

For example, let's say that user A is interested in using DApp, so he provides an email, a name, and a profile picture. So subsequent interactions with DApps, such as comments and posts, will link this user to their respective user data within IPFS.

I would appreciate it if you could give me some advice on how to model users. Thank you!

(Additionally, I'm used to modeling using smart contracts because I use traditional web/mobile apps. So if this is too easy or wrong, I apologize in advance.)